opamp741 said:
Can u remove that resistance from ur circuit..
the characteristic u r trying to plot is very elementry..I never found any problems with that..
If u r still facing problems post ur stimuli and netlist files..
Hi:
I tried the way your suggested, but it gave me the same result. I don't think the resistor will give trouble. You said you never meet problems with that, do you mean you do the parametric sweep for W or L. Becuase I let my friends who take the same course as me to do the same simulation, they also couldn't see the effect. We are using Orcad9.1 student version. If you have ever seen the effect in doing parametric sweep, would you please tell me how did you do it. I posted my stimuli and netlist below, you may can help me to look into it. Thanks.
**** 06/29/04 21:14:08 ********* PSpice 9.1 (Mar 1999) ******** ID# 1000000670
** circuit file for profile: common_amplifier
**** CIRCUIT DESCRIPTION
******************************************************************************
** WARNING: THIS AUTOMATICALLY GENERATED FILE MAY BE OVERWRITTEN BY SUBSEQUENT PROFILES
*Libraries:
* Local Libraries :
.LIB ".\common_source.lib"
* From [PSPICE NETLIST] section of pspice91.ini file:
.lib ".\common_source.lib"
*Analysis directives:
.DC LIN V_Vin 0 5 0.1
.STEP LIN NMOS Mbreakn(W) 2e-6 4e-6 1e-6
.PROBE
.INC "common_source-SCHEMATIC1.net"
**** INCLUDING common_source-SCHEMATIC1.net ****
* source COMMON_SOURCE
V_Vin N00031 0 0Vdc
V_VDD N00018 0 5Vdc
R_R1 N00028 N00018 10k
M_M2 N00028 N00031 0 0 Mbreakn
+ L=1e-6
+ W=2e-6
**** RESUMING common_source-schematic1-common_amplifier.sim.cir ****
.INC "common_source-SCHEMATIC1.als"
**** INCLUDING common_source-SCHEMATIC1.als ****
.ALIASES
V_Vin Vin(+=N00031 -=0 )
V_VDD VDD(+=N00018 -=0 )
R_R1 R1(1=N00028 2=N00018 )
M_M2 M2(d=N00028 g=N00031 s=0 s=0 )
.ENDALIASES
**** RESUMING common_source-schematic1-common_amplifier.sim.cir ****
.END
**** 06/29/04 21:14:08 ********* PSpice 9.1 (Mar 1999) ******** ID# 1000000670
** circuit file for profile: common_amplifier
**** MOSFET MODEL PARAMETERS
******************************************************************************
Mbreakn
NMOS
LEVEL 1
L 100.000000E-06
W 100.000000E-06
VTO .4
KP 100.000000E-06
GAMMA .01
PHI .6
LAMBDA 0
IS 10.000000E-15
JS 0
PB .8
PBSW .8
CJ 0
CJSW 0
CGSO 0
CGDO 0
CGBO 0
TOX 25
XJ 0
UCRIT 10.000000E+03
DIOMOD 1
VFB 0
LETA 0
WETA 0
U0 0
TEMP 0
VDD 0
XPART 0
JOB CONCLUDED
TOTAL JOB TIME .03